Fuel gauge

D

DaveL

New member
I have a 2019 297 SSX. My fuel gauge has been fluctuating all over the place. I had the sending unit replaced and it didn't make any difference. Can anyone recommend a plan B? Thanks.
 
When I used to fly, the Cessna fuel gauges were all over the place. We always had to refer to the manual to check fuel burn rate to determine the length of the flight. I do the same thing with my boat. Fortunately my sending unit is pretty accurate. But I still keep an eye on fuel burn in case it fails.

Plan B for you is short term. Fill the tank and take your boat out on its normal routings. When you've put several hours on it, top the tank again and calculate how much fuel you've burned per hour. My boat is doing about 7gal/hr. In theory, I can operate 10 hours before filling the tank. I rely on the gauge and hours burned at the same time to cross check to make sure my engine is running well, and the gas gauge is accurate and gas in the tank.

I realize this doesn't fix the problem, but this will give you parameters to keep the boat in the water and operating.
 
I had the same problem. Basally, I did what SST did.

I installed a NMEA2K fuel flow sensor. With both the sensor and GPS/MFD connected to the network. The GPS showed my gallons per hour rate. This also showed me my MPG, so I would adjust my speed.
 
Next year my girl will turn 40 and I will have had 33 of them, with 2000 hrs. and still going strong. When I got her she had a bad fuel gauge, so I replaced it. A known factor back then, that gauges were not that good. So like SST and Iggy, I started to do the math with gals per hr. Then you have to put in a fudge factor, but not all conditions are the same. How long did you idle through a no wate zone, how long at a certain rpm, was there a current, and what kind of seas. SSt can tell you about Lake Erie. In the early years I did find a flow meter that worked perfect, it always read a touch higher than what I used. Then it died, and like everything else they made it cheaper and it is not the same one that I had before. So now I have the flow meter, a digitale percentage gauge, an analog gauge, and my gal per hr. They all take turns at being right. My 32 yr. fudge factor is 6 gal per hr. My last fill up was 9 hrs. X 6 = 54 gal, I put in 62 gal. When I had the good flow meter the max I would run between fill ups was 10 hrs. I have an 88 gal tank. Being that my flow meter read high I new that I had a good reserve. Now in today's world of boating and computer engines, the only thing you have to do is remember to fill up.:)
 
I just topped my tank off today, still holding at 7gal/hour. I looked at the gas gauge at dead rise and predicted 55 gallons. I put in 50.1. Not bad for accuracy.

75% of my running time is at cruise settings of 3200rpm @30mph. In the beginning, I wasn't cruising so much as now. More idling as I went up and down parts of the Erie Canal. Fuel burn for this was roughly 5.5Gal/Hour. Nobody believed me but every tank calculation stayed at roughly 5.5. I theorized I could make it from Buffalo to Sandusky without stopping. I never did that run.....I should have. But Lake Erie is to unpredictable.
 
SSt is right. My 30 +years of running, my average is mid to high 5's I cruise between 2300 and 2900 RPM depending on sea conditions and number of people. My 4's kick in at 3100. With my 12"x18" tabs I never have to get into them. I cruise between 20 and 23 MPH, again depending on conditions. (I'm not in any hurry), it's all about the journey for me. I'm not about how fast, it's about how long I am able to enjoy the journey.
 
First season with my Chap. I filed up and thought what I put in at half a tank was half a tank according to the litres I put in. Than last weekend between 1/2 and 1/4 left she ran dry….. we got back in ok. Paddled in about half way with the wind pushing , than a zodiac was fooling around and pulled us in
Only about 1km out front the marina.
 
I almost did the same thing my first year of boating. I come back on E. I knew I had enough fuel, but a small storm was coming. The waves went from 6" to almost 2ft. Than the wind picked up to 10 to 12 knots. I had to slow down which burnt more fuel.

Than I heard of this rule. Always have 1/3 to go out, 1/3 to come back and 1/3 in reserve. I now live by that going out.
 
I've heard about that rule, it is also said when going for a walk in the mountains or desert.
 
I also ran out of gas in my second year. The gauge was always fairly accurate but the sending unit was not. The gauge was down to 1/8th [which I learned was empty] and I was headed home. I was going to take a different route but decided to take the shortest route with a low tank of gas. I made it behind the marinas break wall and pretty close to the gas dock. It ran dry. The wind blew me away from the gas dock and into a private set of docks. Finally, somebody towed me across to the gas dock and I topped the tank. Sometime after that, I put in a new sending unit and it has remained accurate for a very long time. But like I said above. I also compare the gauge indication with estimated fuel burn.
 
I removed the fuel sender today. It was 1/4 or more off. The float wasn’t bent in the right position from when whoever installed it. Also resealed it with some good sealant so maybe that was the source of my Vapor smell also
 
  • Like
Reactions: Doc
You must log in or register to reply here.
Top